Diagram Lines Research Articles

Ab Initio Manganese Kα and Kβ Energy Eigenvalues, Shake-Off Probabilities, Auger Rates, with Convergence Tests.

This work presents ab initio calculations for the Kα spectrum of manganese (Z = 25, [Ar]3d54s2), a highly complex system due to the five open orbitals in the 3d shell. The spectrum is composed of the canonical diagram line [1s]→[2p] and shake-off satellite lines [1snl]→[2pnl] (nl∈{2s,2p,3s,3p,3d,4s}), where square brackets denote a hole state. The multiconfiguration Dirac-Hartree-Fock method with the active set approach provides the initial and final atomic wavefunctions. Results are presented as energy eigenvalue spectra for the diagram and satellite transitions. The calculated wavefunctions include over one hundred million configuration state functions and over 280,000 independent transition energies for the seven sets of spectra considered. Shake-off probabilities and Auger transition rates determine satellite intensities. The number of configuration state functions ensures highly-converged wavefunctions. Several measures of convergence demonstrate convergence in the calculated parameters. We obtain convergence of the transition energies in all eight transitions to within 0.06 eV and shake-off probabilities to within 4.5%.

A lightweight convolutional neural network for working condition intelligent diagnosis of pumping units

Accurate diagnosis of pumping unit working conditions and prompt fault resolution are vital for ensuring safe production in oilfields. In response to the limitations of traditional convolutional neural networks in diagnosing pumping unit working conditions, a lightweight convolutional neural network is proposed. This network addresses the challenges of shallow networks, which cannot effectively extract indicator diagram features, and deep networks, which suffer from excessive parameterization and high redundancy. Firstly, the combination of depthwise separable convolution and dilated convolution efficiently extracts the contour features of the indicator diagram while reducing the model’s parameter count. Additionally, the Attention Embedded Atrous Spatial Pyramid Pooling and the coordinate attention mechanism are incorporated to further capture the shape and position information of indicator diagram lines. The experimental results demonstrate that the proposed lightweight network has 1.26 M parameters and storage size of 4.82 M. Compared to ResNet-50, VGG-16, and MobileNet-V2, its parameter count and storage size are approximately 1/18, 1/11, and 1/2, respectively, making it easily deployable on hardware-limited diagnostic platforms. Moreover, with an average diagnostic accuracy of 98.17%, surpassing existing networks, it enables more effective diagnosis of pumping unit working conditions, thereby enhancing the reliability and accuracy of pumping unit operational monitoring.

Chaotic time delay feature cancellation and bandwidth enhancement in cascaded-coupled nanolasers

As an important part of optical sources, nanolasers have a prominent influence in photonic circuit integration, and their nonlinear dynamics has become one of the research hotspots in recent years. In this work, we investigate the time-delay signature and bandwidth characteristics in a cascade-coupled nanolaser system, in which the master nanolaser is connected to an external feedback cavity and injected into the intermediate nanolaser and the slave nanolaser sequentially. The 0-1 chaos test is introduced to quantify the dynamics of the nanolaser, which can accurately distinguish whether the laser is in a chaotic state, and the autocorrelation function is used to analyze the time-delay characteristics in the laser output signal. This type of calculation has the advantages of fast operation speed, high accuracy and anti-noise robustness. The lower the autocorrelation value, the more difficult it is to extract useful information from the chaotic random sequence. The bandwidth is defined as a value where the range between DC and frequency contains 80% of the spectral power, a value that is only applicable to chaotic states. In the simulation, we compare and analyze the two cases of whether the intermediate nanolaser has a peak with obvious time-delay signature. The research results show that by selecting appropriate system parameters, the slave nanolaser can always output a broadband chaotic signal without obvious time-delay signature. Under the condition of a certain injection intensity, by changing the frequency detuning parameter, the intermediate nanolaser has an obvious time-delay signature, and then the slave nano-laser can output chaotic signals which can suppress time-delay signature and enhance bandwidth in a small parameter interval. When the time-delay signal of the intermediate nanolaser is completely hidden, the slave nanolaser can achieve the suppression of the time-delay signature in a larger parameter plane, meanwhile the bandwidth is significantly enhanced. In addition, by plotting the two-dimensional spatial distribution diagram and bandwidth line diagram of the output from the nanolaser under frequency detuning and injection intensity, it is determined that the nanolaser can simultaneously suppress the delay characteristics and enhance the bandwidth under chaotic signals. This provides an important theoretical basis for realizing the practical applications in secrecy-enhanced chaotic optical communication.

Investigation of Al Kα satellite lines through a high-efficiency multi-channel FSSR

Spectral results of Al diagram lines and satellite lines were obtained using a self-developed high-efficiency multi-channel FSSR.

Design of porous structure based on the Voronoi diagram and stress line for better stress shielding relief and permeability

In the process of artificial metal bone implantation, the mismatch of elastic modulus and bad permeability behavior lead to obvious stress shielding and poor bone tissue ingrowth. For these problems, this paper proposed a new design method of the variable porosity porous structure based on the stress line and Voronoi diagram. In the design process, the principal stress line was determined by mechanical finite element analysis, which controlled the seeds distribution of the 3D Voronoi diagram, making local porosity conforms to the stress distribution. In addition, the designed samples were fabricated through laser powder bed fusion (L-PBF) technology with TC4 powders. The mechanical characteristics were evaluated by static mechanical simulation with ABAQUS and compression tests, and the permeability characteristics were analyzed by fluid simulation with COMSOL and in vitro and vivo test. The research results showed that the designed structure obtained the relatively low elastic modulus and higher mechanical strength, the designed structure has closer permeability characteristics to the reconstructed natural bone, and was conducive to cell proliferation. So the porous structure based on the stress line and Voronoi diagram might have good application potential in the bionic design of bone implants.

Intensity Ratio of Kβ/Kα in Selected Elements from Mg to Cu, and the Chemical Effects of Cr Kα1,2 Diagram Lines and Cr Kβ/Kα Intensity Ratio in Cr Compounds

Kα,β X-ray lines from photon excitation were measured in selected elements from Mg to Cu using a high-resolution double-crystal X-ray spectrometer with a proportional counter, and the Kβ/Kα intensity ratio for each element was obtained, after correcting for self-absorption, detection efficiency, and crystal reflectance. This intensity ratio increases rapidly from Mg to Ca but, in the 3d elements region, the increase becomes slower. This is related to the intensity of the Kβ line involving valence electrons. The slow increase of this ratio in the 3d elements region is thought to be due to the correlation between 3d and 4s electrons. Moreover, the chemical shifts, FWHM, asymmetry indices, and Kβ/Kα intensity ratios of the Cr compounds, due to different valences, were also investigated using the same double-crystal X-ray spectrometer. The chemical effects were clearly observed, and the Kβ/Kα intensity ratio was found to be compound-dependent for Cr.

Theoretical calculation of characteristic radiation: multiconfiguration Dirac–Hartree–Fock calculations in scandium K α and K β

The characteristic x-ray spectra of 3d transition metals are a constant source of advances in atomic physics, x-ray spectrometry, and quantum mechanics. Prior to this work, there was a discrepancy of 0.549 eV between theoretical and experimental results for the scandium Kα 1 peak energy, representing a 55σ discrepancy using the experimental uncertainty. This work improves this to a 0.330 eV discrepancy with only a 4σ error between experiment and theory. Furthermore, we add considerable evidence that asymmetries in x-ray spectra are described by shake events. This work provides ab initio calculations for the diagram and shake-off satellite lines of Sc Kα and Kβ and makes significant improvement on the previous fitting between theory and experiment, from a of 7.35 and 20.85 to 1.60 and 1.45 for Kα and Kβ, respectively. Therefore, we make a strong claim that the asymmetries in scandium x-ray lines exist due to satellite lines with very little room for other hypothesised phenomena to exist, such as Kondo-like interactions and Doniac–Sunjic asymmetries. By fitting to the best experimental data for Sc Kα, β we obtain values for the width and intensity of the satellite lines which enable us to reconstruct the Kα, Kβ profiles.

Structure of single KL0–, double KL1–, and triple KL2 − ionization in Mg, Al, and Si targets induced by photons, and their absorption spectra

We investigated experimentally and theoretically x-ray properties of Mg, Al and Si to assess for new reliable x-ray useful quantities. We measured the KL0– diagram, and KL1– and KL2– satellite lines in Mg, Al, and Si, ionized by photon excitation, using a high-resolution anti-parallel double-crystal x-ray spectrometer. Their energy values, full width at half maxima (FWHM), and relative intensities are obtained by the multiple fitting methods and compared with those reported by other excitation processes. It was found that the relative intensity of Mg and Si KL1 and KL2 satellite lines to the KL0 diagram lines depend on the method used to produce the K hole. The evidence of a new transition between Kα3 and Kα4 in Mg, Al, and S KL1 satellite lines is suggested. These x-ray diagram and satellite lines were investigated theoretically and we found that Mg Kα1,2 diagram lines with hidden satellites are especially in very good agreement with the corresponding experimental ones. Moreover, we also determined the mass attenuation coefficients in a wide energy range covering the K-absorption edge, including a detailed evaluation of the associated uncertainties. From the absorption spectra of Mg and Al, the cross sections of the multi-electron transition processes were estimated and match the theoretical values.

Theory of copper Kα and Kβ diagram lines, satellite spectra, and ab initio determination of single and double shake probabilities

High-accuracy MCDHF Cu Kα and Cu Kβ diagram spectra and major satellites are presented. Spectral eigenvalues reach a theoretical expansion convergence of 0.03 eV or 0.00025%, with gauge and amplitude convergence to 0.7% for Cu Kα diagram spectra. Dominant theoretical spectral eigenvalues are shown to be within 0.032 eV of experimental data. Ab initio shake-off contributions are presented in terms of total probability from each subshell and as separated single and double shake probabilities. Discrepancies between theory and experiment in copper X-ray spectra arise from profile asymmetries, relativistic terms and shake spectra not yet accounted for. These results and this improved agreement provide key fundamental parameters for processes towards XFEL evolution and resolving key discrepancies between theory and experiment.

Kα X-ray satellite spectra of Ge, As, Se and Br by photoionization

First and second order Kα X-ray satellites of the elements Ge, As, Se and Br were investigated by photon excitation. A wavelength dispersive spectrometer with LiF 420 crystal was employed. The energies and relative intensities of these X-ray satellites were measured. Their energy shifts and relative intensities with respect to the Kα diagram line are compared with theoretical estimates. Their dependence on atomic number is also examined.

An Approach to Integrate Product and Process Design Using Augmented Liaison Diagram, Assembly Sequencing, and Assembly Line Balancing

Abstract Concurrent engineering is a product development approach in which engineers simultaneously design products and processes to improve customer satisfaction, enhance product quality, and reduce product costs. While various design methodologies have been proposed to support concurrent engineering, development of a systematic methodology that comprehensively integrates product and process design is still an ongoing research need. Traditional design for assembly (DFA) has been extended to concurrently design subassemblies and assembly sequences; however, the optimum assembly sequence depends on the efficiency of the assembly line and how assembly tasks are assigned to workstations without causing extensive idle time. This study extends past approaches in the concurrent design of products and processes by integrating assembly line balancing, assembly line design, and sensitivity analysis of assembly line design in addition to assembly line sequencing. In particular, this study proposes an approach to simultaneously design products and processes by integrating (1) a liaison diagram augmented with additional information on the type of liaisons (e.g., screw fixing, snap fitting, or contacting) to find stable subassemblies and corresponding assembly tasks, (2) assembly sequencing to generate all feasible assembly sequences that satisfy requirements for stable subassembly, (3) assembly line balancing to identify all possible assignments of tasks to workstations and to find corresponding cycle times and utilization, (4) assembly line designs that include the types and number of assembly lines for each product design, and (5) sensitivity analysis to evaluate the robustness of the assembly line design.

Testing the isomorph invariance of the bridge functions of Yukawa one-component plasmas.

It has been recently conjectured that bridge functions remain nearly invariant along phase diagram lines of constant excess entropy for the broad class of R-simple liquids. To test this hypothesis, the bridge functions of Yukawa systems are computed outside the correlation void with the Ornstein-Zernike inversion method employing structural input from ultra-accurate molecular dynamics simulations and inside the correlation void with the cavity distribution method employing structural input from ultra-long specially designed molecular dynamics simulations featuring a tagged particle pair. Yukawa bridge functions are revealed to be isomorph invariant to a very high degree. The observed invariance is not exact, however, since isomorphic deviations exceed the overall uncertainties.

Structure of Kα1,2 - and Kβ1,3 -emission x-ray spectra for Se, Y, and Zr

The $K\ensuremath{\alpha}$ and $K\ensuremath{\beta}$ x-ray spectra of Se, Y, and Zr were studied experimentally and theoretically in order to obtain information on the $K{\ensuremath{\alpha}}_{1}$ line asymmetry and the spin doublet in $K{\ensuremath{\beta}}_{1,3}$ diagram lines. Using a high-resolution antiparallel double-crystal x-ray spectrometer, we obtained the line shapes, that is, asymmetry index and natural linewidths. We found that the corrected full width at half maximum of the $K{\ensuremath{\alpha}}_{1}$ and $K{\ensuremath{\alpha}}_{2}$ lines as a function of $Z$ is in good agreement with the data in the literature. Furthermore, satellite lines arising from shake-off appear in the low-energy side of the $K{\ensuremath{\alpha}}_{1}$ and $K{\ensuremath{\alpha}}_{2}$ lines in Se but, in Y and Zr, it was very difficult to identify the contribution of the shake process to the overall lines. The $K{\ensuremath{\beta}}_{1,3}$ natural linewidth of these elements was also corrected using the appropriate instrumental function for this type of x-ray spectrometer, and the spin doublet energies were obtained from the peak positions. The corrected full width at half maximum (FWHM) of the $K{\ensuremath{\beta}}_{1}$ x-ray lines increases linearly with $Z$, but this tendency was found to be, in general, not linear for $K{\ensuremath{\beta}}_{3}$ x-ray lines. This behavior may be due to the existence of satellite lines originated from shake processes. Simulated line profiles, obtained using the multiconfiguration Dirac-Fock formalism, accounting for radiative and radiationless transitions and shake-off processes, show a very good agreement with the high-resolution experimental spectra.

Conoscopic image of a biaxial negative in a reentrant discotic – biaxial nematic phase transition

ABSTRACT Conoscopic images have confirmed the occurrence of biaxial positive ( and biaxial negative () nematic phases between the two uniaxial nematic (discotic – and calamitic – ) phases. Biaxial positive () nematic phase was also optically characterised between two uniaxial phases. These nematic phases are found in different phase diagram lines of potassium laurate (), decanol () and deuterium oxide () lyotropic mixtures. In limited concentration range between the two phase diagram lines the following phase sequence ( ) is determined here through conoscopic images. An analysis of the meaning of this result leads us to conclude that the biaxial nematic phase range between uniaxial nematic phases of phase diagrams with nematic lyotropic materials is separated in two regions: one has an optically positive signal and the other, having an optical negative signal.

Energies and emission strengths of Kα X-rays from iodine and gold with multiply ionized L shell

The energies and rates of Kα X-ray satellites due to 1s − 2p transitions in iodine and gold with one to multiple vacancies in the L shell are computed using Multi-Configuration Dirac Fock wavefunctions with the inclusion of relativistic and quantum electrodynamics corrections. The calculations have been carried out for I1+ to I6+ with spectator vacancies in the 2p shell and Au1+ to Au8+ with filled and empty 2s shell along with vacancies in the 2p shell. As existing data on the X-ray emission from low ionized iodine and gold are confined to single inner shell vacancy, direct comparison of the present results on the various radiative transitions from iodine and gold with a single vacancy in the K shell, variously ionized L shell and no vacancy in any other shells is possible only for the two well known Kα 1 and Kα 2 diagram lines. Hence to substantiate the reliability of the current results through one to one comparison with existing data on the 1s − 2p transitions, calculations have also been performed on the radiative decay of H-, He-, Be-, and F-like gold with singly ionized 1s , closed 2s , multiply ionized 2p and rest of the shells open for which semi-relativistic data exist. In addition to providing additional check on the reliability of the computed results, this comparison also tries to analyze the impact of higher order relativistic corrections on the K X-ray energies and rates. The intrinsic variations of transition properties with degree of ionization have been analyzed.

Temperature dependence of 2V angle in biaxial negative and positive nematic lyotropic phases

ABSTRACTRefractive index measurements and conoscopic images has confirmed the occurrence of biaxial negative () and biaxial positive () nematic phases between the two uniaxial nematic (calamitic and discotic ) phases. These nematic phases are found in a phase diagram line of potassium laurate (KL), decanol (, potassium sulfate and water. Biaxial positive ( nematic phase is also optically characterized between two uniaxial phases in a KL, DeOH, and mixture. Temperature dependence of the angles ( and ) between two optic axes of ( and ) phases is obtained from refractive index data. The transition point ( characterized by an angle peak corresponds to the change in the biaxial configuration of the optical axes and optical signal of the biaxial nematic phase. The micellar configuration of biaxial nematic phases is discussed as a consequence of our experimental data.

Precise x-ray energies of gadolinium determined by a combined experimental and theoretical approach

We combined different experimental techniques with a theoretical approach to determine a consistent set of diagram lines energies and binding energies. We propose an original approach consisting in determining the mass attenuation coefficients in an energy range covering the L-, M- and N- absorption edges, including a detailed evaluation of the associated uncertainties, to derive precisely the binding energies. We investigated the Lα, Lβ and M spectra of Gd with an independantly calibrated high-resolution anti-parallel double-crystal x-ray spectrometer. All the lines were identified and found in excellent agreement with the binding energies previously derived. Morever, we identified for the first time M5−O2,M4−O2,3 and M4−N2,3 diagram lines.

KMMRAE structure and Sawada lines of Co, Ni, Cu, Zn and Ga

Kβ spectrum of Co, Ni, Cu, Zn and Ga generated by photoexcitation is studied using a WDXRF spectrometer. KMM RAE structure is de-convoluted into six components. The energy shift of the peaks of these components relative to the diagram line is determined and compared with various theoretical estimates available. The integrated relative intensity of KMM structure is measured. The energy and relative intensity of Sawada lines and Kβ5 peaks are also measured.

Cross section ratios of double-to-single K-shell ionization induced by electron impact in metallic Sc, Cr and Cu targets

The double K-shell ionization of Sc, Cr and Cu induced by electron impact was investigated via high energy resolution measurements of the Kα diagram transitions and the transitions resulting from the radiative decay of K-shell double vacancy states, namely the Khα hypersatellites. For Sc, the Kβ diagram lines and Khβ hypersatellites were also measured. The measurements were carried out in-house with a von Hamos curved crystal spectrometer operated in the so-called direct geometry in which the anodes of Sc, Cr and Cu X-ray tubes were used as targets. For each element, the electron kinetic energy was chosen to be about twice the threshold energy for the double 1s ionization. The double-to-single ionization cross-sections ratios PKK were deduced from the hypersatellite-to-diagram line yield ratios, corrected beforehand for the self-absorption of the X-rays in the target and the energy dependent efficiency of the spectrometer. The obtained ratios are discussed and compared to other PKK values found in the literature for electrons and photons.

Diagram, valence‐to‐core, and hypersatellite Kβ X‐ray transitions in metallic chromium

We report on measurements of the Kβ diagram, valence‐to‐core (VtC), and hypersatellite X‐ray spectra induced in metallic Cr by photon single and double K‐shell ionization. The experiment was carried out at the Stanford Synchrotron Radiation Lightsource using the seven‐crystal Johann‐type hard X‐ray spectrometer of the beamline 6‐2. For the Kβ diagram and VtC transitions, the present study confirms the line shape features observed in previous works, whereas the Khβ hypersatellite transition was found to exhibit a complex spectral line shape and a characteristic low‐energy shoulder. The energy shift of the hypersatellite relative to the parent diagram line was deduced from the measurements and compared with the result of extensive multiconfiguration Dirac–Fock (MCDF) calculations. A very good agreement between experiment and theory was found. The MCDF calculations were also used to compute the theoretical line shape of the hypersatellite. A satisfactory agreement was obtained between the overall shapes of the experimental and theoretical spectra, but deviations were observed on the low‐ and high‐energy flanks of the hypersatellite line. The discrepancies were explained by chemical effects, which were not considered in the MCDF calculations performed for isolated atoms.