bluuebunny/crossref_metadata_2025 huggingface dataset:
Resolving nearby dust clouds
Authors: Leike R. H. , Glatzle M. , Enßlin T. A.
Published: June 2020

Aims. Mapping the interstellar medium in 3D provides a wealth of insights into its inner working. The Milky Way is the only galaxy for which detailed 3D mapping can be achieved in principle. In this paper, we reconstruct the dust density in and around the local super-bubble.

Methods. The combined data from surveys such as Gaia, 2MASS, PANSTARRS, and ALLWISE provide the necessary information to make detailed maps of the interstellar medium in our surrounding. To this end, we used variational inference and Gaussian processes to model the dust extinction density, exploiting its intrinsic correlations.

Results. We reconstructed a highly resolved dust map, showing the nearest dust clouds at a distance of up to 400 pc with a resolution of 1 pc.

Conclusions. Our reconstruction provides insights into the structure of the interstellar medium. We compute summary statistics of the spectral index and the 1-point function of the logarithmic dust extinction density, which may constrain simulations of the interstellar medium that achieve a similar resolution.
Gas, dust, and star formation in the positive AGN feedback candidate 4C 41.17 at z = 3.8
Authors: Nesvadba N. P. H. , Bicknell G. V. , Mukherjee D. , Wagner A. Y.
Published: June 2020

We present new, spatially resolved [CI]1–0, [CI]2–1, CO(7–6), and dust continuum observations of 4C 41.17 at z = 3.8. This is one of the best-studied radio galaxies in this epoch and is arguably the best candidate of jet-triggered star formation at high redshift currently known in the literature. 4C 41.17 shows a narrow ridge of dust continuum extending over 15 kpc near the radio jet axis. Line emission is found within the galaxy in the region with signatures of positive feedback. Using the [CI]1–0 line as a molecular gas tracer, and multifrequency observations of the far-infrared dust heated by star formation, we find a total gas mass of 7.6 × 1010 M⊙, which is somewhat greater than that previously found from CO(4–3). The gas mass surface density of 103 M⊙ yr−1 pc−2 and the star formation rate surface density of 10 M⊙ yr−1 kpc−2 were derived over the 12 kpc × 8 kpc area, where signatures of positive feedback have previously been found. These densities are comparable to those in other populations of massive, dusty star-forming galaxies in this redshift range, suggesting that the jet does not currently enhance the efficiency with which stars form from the gas. This is consistent with expectations from simulations, whereby radio jets may facilitate the onset of star formation in galaxies without boosting its efficiency over longer timescales, in particular after the jet has broken out of the interstellar medium, as is the case in 4C 41.17.
Déterminants d’adoption des techniques de production et protection intégrées pour un maraîchage durable à Lubumbashi, République démocratique du Congo
Authors: Mushagalusa Balasha Arsene , Nkulu Mwine Fyama Jules
Published: June 2020

La production maraîchère est une filière importante de l’agriculture urbaine et périurbaine en Afrique. En République démocratique du Congo, un projet d’horticulture urbaine et périurbaine a été mis en place avec l’appui technique de l’Organisation des Nations Unies pour l’alimentation et l’agriculture pour vulgariser des techniques de production et protection intégrées. Les techniques promues comprenaient l’usage des fertilisants naturels, des extraits de plantes à effet insecticide, des produits naturels de lutte contre les ravageurs, les associations et les rotations culturales, l’usage raisonné des pesticides en dernier recours, ainsi que l’utilisation de variétés résistantes aux maladies. Le modèle Logit a permis d’analyser les données d’enquête d’un échantillon de 246 maraîchers à Lubumbashi entre mars et juin 2016 pour identifier les facteurs favorisant l’adoption des techniques promues. L’appartenance à une association de maraîchers et la formation reçue en maraîchage sont deux facteurs clés qui influencent positivement et significativement l’adoption des techniques de production et protection intégrées, respectivement de 3,5 à 7 fois plus que les agriculteurs n’appartenant pas à une association ou n’ayant pas reçu de formation. Ces résultats suggèrent que la participation des agriculteurs à des ateliers de formation et à des groupes de discussion au travers de champs-écoles peut servir de catalyseur pour accroître l’adoption de techniques innovantes en maraîchage.
Focalization of electromagnetic power at the interface between two composites materials for induction welding
Authors: Kane Banda , Wasselynck Guillaume , Bui Huu Kien , Trichet Didier , Berthiau Gérard
Published: June 2020

This paper presents a fast-numerical approach to optimize the localization of induced power in highly anisotropic composite materials with a large-scale factor. A one-dimensional hybrid multi-physical tool allows us to find the best ply sequence and the best strategy to constrain the induced currents to circulate in an interest area defined respecting specific temperature objectives. A three-dimensional multi-physical modeling is then used on a few selected candidates to refine results.
Design, fabrication and characterization of an electrical-explosively actuated MEMS flyer-accelerator inserted with parallel bridge foils
Authors: Yang Zhi , Zheng Guoqiang , Zhu Peng , Xu Cong , Zhang Qiu , Wang Ke , Shen Ruiqi
Published: June 2020

Parallel bridge foils (PBF) with four strip foils, which is derived from traditional single bridge foil (SBF), was designed to study the effect of convergence and collision of plasmas and shock waves on driving flyer. Firstly, Electro-thermal simulation of PBF was performed to analyze temperature distribution before melting, which predicted the synchronous burst characteristic of PBF. Subsequently, a capacitor discharging circuit was designed to initiate bridge foils, results indicated PBF reached higher burst power in shorter time compared with SBF due to better matching between PBF and the test circuit. The flow fields of electrical explosion of bridge foils were photographed by ultra-high-speed camera, which displayed PBF almost burst simultaneously. Moreover, PBF had wider and brighter flow field visualization than SBF owing to convergence and superposition of plasma beams. Most importantly, flyer-accelerators inserted with bridge foils were prepared by MEMS technology, and comparative analysis from PDV revealed MEMS flyer-accelerator inserted with PBF had access to better velocity performances, compared with that inserted with SBF. For instance, PBF flyer-accelerator spent mere 168 ns to 2325 m/s at 900 V/0.22 µF, but SBF flyer-accelerator took 335 ns to 1073 m/s. Finally, we proposed a mathematical model for explaining the enhancement effect of flyer velocity, which to some extent showed good agreement with experimentation.
Erfassung von Funktionseinschränkungen bei Patienten mit chemotherapieinduzierter Polyneuropathie
Authors: Köppel Maximilian , Bannasch Marcel , Huber Gerhard , Wiskemann Joachim
Published: June 2020

Hintergrund Infolge des Einsatzes neurotoxischer Chemotherapeutika leiden viele Krebspatienten und -überlebende unter chemotherapieinduzierten peripheren Neuropathien (CIPN). Diese Nebenwirkung der Chemotherapie ist mit einem hohen Leidensdruck assoziiert und beeinträchtigt die Autonomie der Patienten. Bewegungstherapeutische Interventionsstudien können den Verlauf der CIPN positiv beeinflussen. Zur Sicherung der Ergebnisqualität in der bewegungstherapeutischen Praxis bedarf es testökonomischer und valider Assessmentverfahren.

Methoden 20 Krebspatienten und –überlebende mit CIPN (Alter: 63 Jahre, SD = 9) wurden eingeschlossen. Die Patienten führten den Jebsen Taylor Handfunktionstest (JTT) als Indikator der motorischen Fähigkeiten der oberen Extremität (OE) und einen Pertubationstest in medio-laterale (MLP) sowie anterio-posteriore Richtung (APP) als Indikator der posturalen Stabilität der unteren Extremität (UE) auf dem Posturomed durch. Daneben füllten die Teilnehmer einen Fragebogen zur Erfassung der Einschränkungen der Alltagsaktivitäten (ADL-Fragebogen) sowie den EORTC-QLQ-CIPN20 aus. Zur Prüfung der konvergenten Validität wurde die prädiktive Kraft der motorischen Tests auf die korrespondierenden Fragebogenskalen mittels einfacher linearer Regressionsanalyse berechnet.

Ergebnisse Zwischen der Skala zur OE des ADL-Fragebogens und dem JTT wurde ein Zusammenhang von rsp(18)= 0,507 (p = 0,023) für die nicht-dominante sowie ein Zusammenhang von rsp(18)= 0,417 (p = 0,067) für die dominante Hand gefunden. Das Regressionsmodell ergibt hierbei, dass eine ADL-Einschränkung einer Veränderung der mittleren im JTT der nicht-dominanten Hand benötigten Zeit von 2,63 s ist. Der MLP zeigte einen Zusammenhang von r(17)= 0,54 (p = 0,038) mit der Skala zur Unteren Extremität des ADL-Fragebogens. Hierbei entspricht eine ADL-Einschränkung einer Veränderung um 22,7 Punkten im Koordinationsfaktor des MLP.

Diskussion Die Ergebnisse zeigen, dass sowohl der JTT als auch der MLP konvergenzvalide für den Einsatz bei Patienten mit CIPN ist und praktisch relevante Effektgrößen hinsichtlich der Bewältigung von Alltagsaktivitäten ableiten lassen.

Limitationen Wegen der kleinen Stichprobe und die Limitierung der statistischen Verfahren können die gefundenen Ergebnisse zwar eine Orientierung geben, dürfen allerdings aufgrund ihrer großen Unschärfe nicht als exakte Punktschätzer angesehen werden. Es bedarf longitudinaler Daten mit größeren Stichproben.
Long-term Stack splint immobilization for closed tendinous Mallet Finger
Authors: Hong In Tae , Baek Eugene , Ha Cheungsoo , Han Soo-Hong
Published: June 2020

Background Closed tendinous mallet finger can be treated non-operatively by extension splinting of the distal interphalangeal joint (DIPJ) for 6 to 8 weeks. However, method of conservative treatment in detail differs among various reports, especially in type of orthosis, duration of full-time immobilization and additional night orthotic wear after full-time immobilization. In our institution, full-time Stack splint is applied with distal interphalangeal joint (DIPJ) in extension for 12 weeks and night orthosis is worn for 4 weeks.

Purpose The purpose of this study was to evaluate clinical and functional outcomes of tendinous mallet finger using our treatment protocol.

Patients and Methods Between March 2007 and December 2017, patients with tendinous mallet finger who were managed conservatively according to our treatment protocol were retrospectively reviewed. A total of 100 patients (101 cases) were enrolled, including 77 males and 23 females. Extension lag was measured before, soon after treatment, and at the final follow-up. Flexion angle of DIP joint was measured at the final follow-up. Patients were clinically evaluated based on the Crawford classification scale and Abouna & Brown criteria.

Results The mean age of patients was 40 years and the mean follow-up was 48 months. The mean extension lag was 28.3 degrees initially and 2.6 degrees at the final follow-up. (p-value < 0.001) Flexion angle at the final follow-up was 68.3 degrees. Based on the Crawford classification scale, 56 % of patients had excellent results, and 25 % of patients had good results. According to Abouna & Brown criteria, 78 % of patients had success results and 7.5 % of patients had improved results.

Conclusions Wearing orthosis for up to 16 weeks (12 weeks full time and 4 weeks night orthosis) in the treatment of tendinous mallet finger injuries can achieve satisfying result.
The Use of Doppler Ultrasound to Assess the Blood Flow of Pedicled Vascularized Bone Grafting for Scaphoid Nonunions
Authors: Jerome J. Terrence Jose , Venkatachalam Ilayaraja
Published: June 2020

Objectives This study aims to assess the blood flow and the vascularity pattern across the newly bridged vascularized bone grafts for scaphoid nonunions using three-dimensional (3D) high frequency power Doppler ultrasonography and its role in the union.

Materials and Methods A total of 26 patients with scaphoid nonunions were operated with 1,2-intercompartmental supraretinacular artery (ICSRA) graft. CT scan and 3D high frequency power Doppler ultrasonography were performed in all patients between 12 and 18 weeks, and its results were analyzed.

Results Doppler ultrasonography confirmed the pulsatile flow and vascularity across the pedicle and vascularized bone graft incorporation into the scaphoid nonunion site.

Conclusions 3D high frequency power Doppler ultrasonography is a simple, noninvasive, nonradiation, reproducible, and well-reliable diagnostic modality in assessing the blood flow and vascularity of the bone grafts used for scaphoid nonunions.

Level of Evidence This is a Level IV study.
Limited Carpal Fusion in Kienböck's Disease: Early Results following Scaphocapitate Arthrodesis
Authors: Goyal Nikhil , Singh Vivek , Barik Sitanshu , Behera Santosh
Published: June 2020

Background Kienböck's disease leading to progressive carpal collapse alters the wrist biomechanics leading to early arthritis and degenerative changes. Out of multiple surgical procedures present, no gold standard has been described. Scaphocapitate arthrodesis (SCA) is limited carpal fusion which shifts the loading axis toward radioscaphoid joint. This study presents the midterm clinical and radiological results of SCA in Kienböck's disease.

Materials and Methods The data were reviewed from January 2016 to December 2017. Lichtman's classification used to stage the disease. Clinical variables were noted for wrist range of motion, grip strength, visual analog scale (VAS) score, quick disabilities of the arm, shoulder, and hand (quickDASH), and patient-rated wrist evaluation (PRWE) scores. Radiographs were evaluated for union, ulnar variance, carpal height ratio, radioscaphoid angle, and scapholunate angle.

Results A total of 11 patients of Stage IIIA and IIIB Kienböck's disease with mean age of 24 years were included in the study with a minimum of 18 months of clinical follow-up. The procedure resulted in decreased ranges of motion but improved grip strength (26.09 ± 4.76 from 19.54 ± 4.63 kgf) and reduced pain with VAS score decreased from 7.36 ± 0.8 to 2 ± 1. Radiographic analysis showed union in all patients, reduced carpal height with a corrected radioscaphoid angle (from 62.12 to 48.3 degrees), and scapholunate angle (from 34 to 26.27 degrees).

Discussion SCA has advantage of technical ease of orientation of the scaphoid and osteosynthesis of only one intercarpal joint with a large contact surface. Coupling the distal and proximal carpal rows results in significant loss of mean wrist range of motion but with improved grip strength, shifting the load away from the radiolunate joint. However, long-term studies are needed for clinical benefits and radiographic signs of radioscaphoid arthritis for the treatment of advanced-stage Kienböck's disease.

Level of Evidence This is a Level IV, retrospective observational study.
Decay of regular solutions for the critical 2D Zakharov–Kuznetsov equation posed on rectangles
Authors: Larkin N. A.
Published: June 2020

An initial-boundary value problem for the critical generalized 2D Zakharov–Kuznetsov equation posed on rectangles is considered. The existence, uniqueness, and exponential decay rate of global regular solutions for small initial data are established.
The Langmuir probe system in the Wendelstein 7-X test divertor
Authors: Rudischhauser L. , Endler M. , Höfel U. , Hammond K. C. , Kallmeyer J. P. , Blackwell B. D. ,   Wendelstein 7-X Team
Published: June 2020

The design and evaluation of the Langmuir probe system used in the first divertor operation phase of Wendelstein 7-X is described. The probes are integrated into the target plates and have individually facetted surfaces to keep the angle of incidence of the magnetic field within an appropriate range for different magnetic configurations. Multiple models for the derivation of plasma parameters from current–voltage characteristics are introduced. These are analyzed with regard to their assumptions and limitations, generalized, and adapted to our use case. A detailed comparison is made to determine the most suitable model. It is found that the choice of model has a large impact, for example, resulting in a change in the inferred temperatures of up to a factor two. This evaluation is implemented in a Bayesian modeling framework and automated to allow for joint analysis with other diagnostics and a replacement of ad hoc assumptions. We rigorously treat parameter uncertainties, revealing strong correlations between them. General and flexible model formulations permit an expansion to additional effects.
Influence of domain size on direct numerical simulation of turbulent flow in a moderately curved concentric annular pipe
Authors: Bagheri Edris , Wang Bing-Chen , Yang Zixuan
Published: June 2020

Direct numerical simulation (DNS) of turbulent flow in a concentric annular pipe was performed using a pseudo-spectral method computer code. In order to study the effects of computational domain size on the turbulence statistics, 12 test cases of different domain sizes are compared. The characteristics of the velocity field are examined at two different Reynolds numbers. It is observed that the predictive accuracy of the first- and second-order statistics is sensitive to the axial and azimuthal domain sizes. It is also found that the scales and dynamics of turbulence structures vary with the surface curvature of the concave and convex walls. The characteristic length scales of the turbulence structures are identified through a spectral analysis, and it is observed that a minimum computational domain is required in order to accurately capture the near-wall streaky and hairpin structures of a concentric annular pipe flow using DNS.
Non-adiabatic molecular dynamics with divide-and-conquer type large-scale excited-state calculations
Authors: Uratani Hiroki , Nakai Hiromi
Published: June 2020

Many of the non-adiabatic processes in the condensed phase are affected by the interaction with the environment, as exemplified by Marcus theory. However, non-adiabatic molecular dynamics simulations with explicitly including the environment are computationally expensive because of the extended system size, suggesting the need for an efficient scheme applicable to huge systems. In this work, time-derivative non-adiabatic coupling (TDNAC) calculation algorithms were developed in the framework of the divide-and-conquer (DC) time-dependent (TD) density-functional tight-binding (DFTB) method, which is an extension of the TD-DFTB for larger systems based on the fragmentation-based DC scheme. The developed algorithms were incorporated into a fewest-switches trajectory surface hopping (FSSH) routine. The calculated TDNAC and the FSSH results were sufficiently accurate compared to the conventional TD-DFTB results. Use of the DC-TD-DFTB provided a significant reduction in the central processing unit (CPU) time vs that of the TD-DFTB, where the CPU time remained constant irrespective of the total system size. It was also confirmed that the present method is not only efficient but also improves the numerical stability of TDNAC calculations.
Numerical simulation of high-efficiency, scalable, all-back-contact Cd(Se,Te) solar cells
Authors: Nardone M. , Spehar M. , Kuciauskas D. , Albin D. S.
Published: June 2020

All-back-contact thin-film photovoltaic devices in lattice back contact (LBC) configuration are studied by device simulation to set the requirements for achieving efficiency >20% with lateral contact spacing >50 μm. The numerical device model is first validated against published data for an LBC perovskite device and extended to predict the performance of Cd(Se,Te)-based polycrystalline devices. Recent advances in the electronic properties of Cd(Se,Te) films have made high efficiency LBC devices feasible with industrially scalable contact dimensions. Constraints on bulk, interface, and contact properties are quantified and discussed.
Extreme singular events associated with inertial-viscous cusp formation in fluids
Authors: Raja D. Krishna , Das S. P. , Hopfinger E. J.
Published: June 2020

Cusp singularities in fluids have been experimentally demonstrated in the past only at a low Reynolds number, Re ≪ 1, and large capillary number, Ca ≫ 1, in Newtonian or non-Newtonian fluids. Here, we show that the collapse of a free surface wave depression cavity can lead to inertial-viscous cusp formation at local Re > 1 and Ca > 1, which gives rise to extreme events, i.e., very high-velocity surface jets. The cavities are generated in a cylindrical container (2R = 10 cm), partially filled with glycerine–water solution, by parametrically forcing the axi-symmetric wave mode beyond the breaking limit. By varying the forcing amplitude and the fluid viscosity, parabolic or cusp singularities manifest, depending on the last stable wave amplitude b that determines the cavity shape. Cusp formation in collapse without bubble pinch-off, leading to very high-velocity surface jets, is obtained when b is close to the singular wave amplitude bs and Ca > 1. The free surface shape is self-similar, changing from an inertial to a viscous regime when the singularity is approached. At cusp singularity, the cavity shape takes the form of (z − Z0)/R ∼ −(r/R)2/3, where Z0 is the final cavity depth. Cavity collapse with bubble pinch-off, which occurs when b > bs, also exhibits a cusp singularity when bs < b ≤ 1.14 bs and Ca > 1, but surface jet velocities are much less because about half of the wave energy is lost.
Hysteric photo-conduction and negative differential resistance in cesium lead bromide
Authors: Kumar Manish , Jha Priyanka A. , Jha Pardeep K. , Singh Prabhakar
Published: June 2020

For the perovskite halides, current voltage hysteresis is the biggest puzzle to be solved before industrialization in spite of promising features for future photo-voltaic applications. All the possible causes, from the classical (viz., morphology, defects, slow transient capacitance, etc.) to quantum (viz., spin–orbit interaction) ones, are investigated. However, its origin is still under debate, as possibilities showed some ambiguity on the science known until now. In the present work, we have studied the time dependent photo-conduction behavior of CsPbBr3 in continuous illumination of AM 1.5 G Sun light for 3 h. We observed a negative differential resistance for a forward scanned current–voltage curve in AM 1.5 G Sun light. Our investigations suggest that the photo-current voltage hysteresis is primarily affected by the thermionic-field emission, which slows down the drift velocity of hot charge carriers with field applications. This study will further lead the scientific community to investigate whether this slowdown in drift velocity is related to the Gunn effect or the Rashba effect.
Loss of ZIP facilitates JAK2-STAT3 activation in tamoxifen-resistant breast cancer
Authors: Zhu Ning , Zhang Jing , Du Yuping , Qin Xiaodong , Miao Ruidong , Nan Jing , Chen Xing , Sun Jingjie , Zhao Rui , Zhang Xinxin , Shi Lei , Li Xin , Lin Yuxi , Wei Wei , Mao Aihong , Zhang Zhao , Stark George R. , Wang Yuxin , Yang Jinbo
Published: June 2020

Tamoxifen, a widely used modulator of the estrogen receptor (ER), targets ER-positive breast cancer preferentially. We used a powerful validation-based insertion mutagenesis method to find that expression of a dominant-negative, truncated form of the histone deacetylase ZIP led to resistance to tamoxifen. Consistently, increased expression of full-length ZIP gives the opposite phenotype, inhibiting the expression of genes whose products mediate resistance. An important example is
JAK2
. By binding to two specific sequences in the promoter, ZIP suppresses
JAK2
expression. Increased expression and activation of JAK2 when ZIP is inhibited lead to increased STAT3 phosphorylation and increased resistance to tamoxifen, both in cell culture experiments and in a mouse xenograft model. Furthermore, data from human tumors are consistent with the conclusion that decreased expression of ZIP leads to resistance to tamoxifen in ER-positive breast cancer.
The 2020 photovoltaic technologies roadmap
Authors: Wilson Gregory M , Al-Jassim Mowafak , Metzger Wyatt K , Glunz Stefan W , Verlinden Pierre , Xiong Gang , Mansfield Lorelle M , Stanbery Billy J , Zhu Kai , Yan Yanfa , Berry Joseph J , Ptak Aaron J , Dimroth Frank , Kayes Brendan M , Tamboli Adele C , Peibst Robby , Catchpole Kylie , Reese Matthew O , Klinga Christopher S , Denholm Paul , Morjaria Mahesh , Deceglie Michael G , Freeman Janine M , Mikofski Mark A , Jordan Dirk C , TamizhMani Govindasamy , Sulas-Kern Dana B
Published: June 2020

Over the past decade, the global cumulative installed photovoltaic (PV) capacity has grown exponentially, reaching 591 GW in 2019. Rapid progress was driven in large part by improvements in solar cell and module efficiencies, reduction in manufacturing costs and the realization of levelized costs of electricity that are now generally less than other energy sources and approaching similar costs with storage included. Given this success, it is a particularly fitting time to assess the state of the photovoltaics field and the technology milestones that must be achieved to maximize future impact and forward momentum. This roadmap outlines the critical areas of development in all of the major PV conversion technologies, advances needed to enable terawatt-scale PV installation, and cross-cutting topics on reliability, characterization, and applications. Each perspective provides a status update, summarizes the limiting immediate and long-term technical challenges and highlights breakthroughs that are needed to address them. In total, this roadmap is intended to guide researchers, funding agencies and industry in identifying the areas of development that will have the most impact on PV technology in the upcoming years.
Topological phases arising from attractive interaction and pair hopping in the extended Hubbard model
Authors: Rausch Roman , Peschke Matthias
Published: June 2020

The extended Hubbard model with an attractive density–density interaction, positive pair hopping, or both, is shown to host topological phases, with a doubly degenerate entanglement spectrum and interacting edge spins. This constitutes a novel instance of topological order which emerges from interactions. When the interaction terms combine in a charge-SU(2) symmetric fashion, a novel partially polarized pseudospin phase appears, in which the topological features of the spin degrees of freedom coexist with long-range η-wave superconductivity. Thus, our system provides an example of an interplay between spontaneous symmetry breaking and symmetry-protected topological order that leads to novel and unexpected properties.
Surface-regulated triangular borophene as Dirac-like materials from density functional calculation investigation*
Authors: Fang Wenyu , Kang Wenbin , Zhao Jun , Zhang Pengcheng
Published: June 2020

By applying the first principles calculations combined with density functional theory (DFT), this study explored the optical properties, electronic structure, and structure stability of triangular borophene decorated chemically, B3
X (X = F, Cl) in a systematical manner. As revealed from the results of formation energy, phonon dispersion, and molecular dynamics simulation study, all the borophene decorated chemically were superior and able to be fabricated. In the present study, triangular borophene was reported to be converted into Dirac-like materials when functionalized by F and Cl exhibiting narrow direct band gaps as 0.19 eV and 0.17 eV, separately. Significant light absorption was assessed in the visible light and ultraviolet region. According the mentioned findings, these two-dimensional (2D) materials show large and wide promising applications for future nanoelectronics and optoelectronics.
Fast and accurate determination of phase transition temperature via individual generalized canonical ensemble simulation*
Authors: Shao Ming-Zhe , Wang Yan-Ting , Zhou Xin
Published: June 2020

It is very important to determine the phase transition temperature, such as the water/ice coexistence temperature in various water models, via molecular simulations. We show that a single individual direct simulation is sufficient to get the temperature with high accuracy and small computational cost based on the generalized canonical ensemble (GCE). Lennard–Jones fluids, the atomic water models, such as TIP4P/2005, TIP4P/ICE, and the mW water models are applied to illustrate the method. We start from the coexistent system of the two phases with a plane interface, then equilibrate the system under the GCE, which can stabilize the coexistence of the phases, to directly derive the phase transition temperature without sensitive dependence on the applied parameters of the GCE and the size of the simulation systems. The obtained result is in excellent agreement with that in literatures. These features make the GCE approach in determining the phase transition temperature of systems be robust, easy to use, and particularly good at working on computationally expensive systems.
Multiphoton quantum dynamics of many-electron atomic and molecular systems in intense laser fields*
Authors: Li Peng-Cheng , Chu Shih-I
Published: June 2020

We present the recent new developments of time-dependent Schrödinger equation and time-dependent density-functional theory for accurate and efficient treatment of the electronic structure and time-dependent quantum dynamics of many-electron atomic and molecular systems in intense laser fields. We extend time-dependent generalized pseudospectral (TDGPS) numerical method developed for time-dependent wave equations in multielectron systems. The TDGPS method allows us to obtain highly accurate time-dependent wave functions with the use of only a modest number of spatial grid point for complex quantum dynamical calculations. The usefulness of these procedures is illustrated by a few case studies of atomic and molecular processes of current interests in intense laser fields, including multiphoton ionization, above-threshold ionization, high-order harmonic generation, attosecond pulse generation, and quantum dynamical processes related to multielectron effects. We conclude this paper with some open questions and perspectives of multiphoton quantum dynamics of many-electron atomic and molecular systems in intense laser fields.
Structure and tribological properties of Si/a-C:H(Ag) multilayer film in stimulated body fluid*
Authors: Wu Yan-Xia , Liu Yun-Lin , Liu Ying , Zhou Bing , Hei Hong-Jun , Ma Yong , Yu Sheng-Wang , Wu Yu-Cheng
Published: June 2020

Si/a-C:H(Ag) multilayer films with different modulation periods are prepared to test their potential applications in human body. The composition, microstructure, mechanical and tribological properties in the simulated body fluid are investigated. The results show the concentration of Ag first decreases and then increases with the modulation period decreasing from 984 nm to 250 nm. Whereas the C content has an opposite variation trend. Notably, the concentration of Ag plays a more important role than the modulation period in the properties of the multilayer film. The a-C:H sublayer of the film with an appropriate Ag concentration (8.97 at.%) (modulation period of 512 nm) maintains the highest sp3/sp2ratio, surface roughness and hardness, and excellent tribological property in the stimulated body fluid. An appropriate number of Ag atoms and size of Ag atom allow the Ag atoms to easily enter into the contact interface for load bearing and lubricating. This work proves that the Ag nanoparticles in the a-C:H sublayer plays a more important role in the tribological properties of the composite-multilayer film in stimulated body fluid condition.
Photodetachment of C− in the ground state
Authors: Marion R , Dunseath K M , Terao-Dunseath M , Urbain X
Published: June 2020

Synopsis

Absolute total cross sections and asymmetry parameters for photodetachment of C− (4So) have been measured using animated-crossed-beam and velocity map imaging techniques, for photon energies from threshold up to 6eV. The cross sections are 15% to 25% larger than earlier experimental results above 2.2 eV. They are in very good agreement with those from a new R-matrix calculation using polarized pseudostates.
Double photoionization of atomic carbon and neon
Authors: Yip F L , Rescigno T N , McCurdy C W
Published: June 2020

Synopsis

We consider the double photoionization of the 2p2 valence electrons of atomic carbon, which provides for distinct final-state symmetries depending on the three possible angular momentum couplings (3P, 1
D, and 1S) of the initially-bound p2 electrons that are ejected into the continuum by a single photon. Comparison of this process with neon provides an analogous case for the resulting final states within the treatment of the double photoionization proceeding with the ejected electrons influenced by the remaining bound electrons.
An experimental and theoretical investigation of XPS and NEXAFS of nicotine, nicotinamide, and nicotinc acid
Authors: Sa’adeh H , Backler F , Wang F , Ciavardini A , Piccirillo S , Coreno M , Richter R , Prince K C
Published: June 2020

Synopsis

The electronic structures of nicotine, nicotinic acid and nicotinamide have been studied by valence photoemission spectroscopy (PES), core X-ray photoelectron spectroscopy (XPS), and near-edge X-ray absorp-tion fine structure (NEXAFS) and interpreted with the aid of quantum chemical calculations. Nicotinamide and nicotinic acid are closely related and show correspondingly similar spectral features, while nicotine is both structurally and spectroscopically diverse.
Effects of exchange-correlation functionals on the structure and the photoionization dynamics of Na40 versus Na92 cluster
Authors: Shaik R , Varma H R , Chakraborty H S
Published: June 2020

Synopsis

We study the photoionization properties of the Nan (n=40 and 92) clusters in a spherical jellium frame using the Kohn-Sham density functional method. Two well known form of exchange-correlation (xc) functional in the framework of local density approximation (LDA) with Gunnarsson-Lundqvist parametrization[1] are employed: i) the electron self-interaction correction (LDA-SIC) [1] and ii) the van Leeuwen and Baerends model potential (LDA-LB94) [1].
X-ray spectroscopy on ultrafast-decaying core-excited atomic ions
Authors: Ilchen M , Mazza T , Baumann T M , Boll R , De Fanis A , Grychtol P , Music V , Ovcharenko Y , Rivas D , Berrah N , Erk B , Gryzlova E , Johnsson P , Küstner-Wetekam C , Marder L , Martins M , Ott Ch , Pathak S , Pfeifer Th , Rolles D , Schmidt P , Grum-Grzhimailo A , Meyer M
Published: June 2020

Synopsis

Results from the first soft X-ray user experiment at the European XFEL on nonlinear photon-matter interaction will be presented. Angle-resolved electron time-of-flight spectroscopy employed at the AQS (Atom-ic-like Quantum Systems) endstation of the SQS (Small Quantum Systems) instrument reveals insight into the character of resonances in highly transient, core ionized neon ions, i.e. Ne+ 1s12s22p6 → Ne+* 1s02s22p6np, together with their respective relaxation dynamics. Enabled by the unique properties of the European XFEL, novel perspectives on efficient nonlinear spectroscopy will be discussed.
Two-color VUV+IR multiphoton ionization of the He+ ion by circularly polarized light in the region of the 3p excited state
Authors: Grum-Grzhimailo A N , Douguet N , Bartschat K
Published: June 2020

Synopsis

Circular dichroism in the two-color XUV + IR ionization of He+ is considered theoretically in connection with the recent experiment by Ilchen et al. [1]. The sharp decrease of the circular dichroism with increasing intensity of the IR field when the XUV frequency is near the 1s – 3p resonant excitation is studied. It is confirmed that the main source of the effect is the axial component of the polarizability, which has opposite signs for magnetic substates with opposite projections.
Collisions between cold molecules in a superconducting magnetic trap
Authors: Pitzer M , Segev Y , Karpov M , Akerman N , Narevicius J , Narevicius E
Published: June 2020

Synopsis

We decelerate and trap molecular oxygen using time-dependent magnetic fields and superconducting magnets. The density-dependent, non-exponential decay in particle number provides a clear proof of molecule-molecule collisions within the trapped ensemble. The spatial distribution of molecules in the trap is found to change over time, allowing to set limits on the ratio between the elastic and inelastic collision cross sections. Our experimental scheme opens up new possibilities for studying quantum effects in chemistry as well as for evaporative cooling of molecules.
A traveling wave Zeeman decelerator
Authors: Damjanovic T , Vanhaecke N , Cromiéres J , Haak H , Meijer G , willitsch S , Zhang D
Published: June 2020

Synopsis

We developed a new-concept Zeeman decelerator which produces a traveling magnetic trap. Atoms and molecules possessing a magnetic dipole moment, in so-called low field seeking states, are trapped around a node of a propagating wave provided that the initial velocity of the wave matches a velocity populated in the supersonic beam. In addition, three dimensional confinement is achieved by controlling the radial orientation of the trap, which can be done fully independently from its longitudinal motion.
Calculations of long-range three-body interactions for Li(2 2S )-Li(22 S )-Li+(1 1S)
Authors: Yan P G , Tang L Y , Yan Z C , Babb J F
Published: June 2020

Synopsis

Using perturbation theory for energies, we evaluate the additive and nonadditive interaction co-efficients C4, C6
, C7
, C8
and C9 for the Li(22S)-Li(22S)-Li+(11S) system. The obtained coefficients Cn are evaluated with highly accurate variationally-generated nonrelativistic wave functions in Hylleraas coordinates. The nonadditive interaction coefficients depend on the geometrical configurations of this three-body system and on the different position of the ion for each configuration. Our calculations may be of interest for the study of three-body recombination and for constructing precise potential energy surfaces.
Development of a cryogenic ion mobility spectrometer for an isomer-selected photoexcitation and reaction studies
Authors: Shiina Y , Takaya K , Ueta H , Hirayama T , Nakano Y
Published: June 2020

Synopsis

A new development aiming experimental studies of isomer-selected gas-phase reactions and photoexcitation processes is being conducted. The experiment is based on isomer separation by an ion mobility spectrometry and ion accumulation in a temperature-variable radiofrequency ion trap. The laser plasma light source at Rikkyo University is currently under an upgrade for providing ultraviolet light at the wavelength region from 90 to 200 nm. We report on the details of the experimental setup and current status of the development.
Formation of

H3−

molecular ions by Three-Body Recombination
Authors: Silva H da , Dulieu O , Raoult M
Published: June 2020

Synopsis

The simplest triatomic molecular ion

H
3
−

, is predicted to be stable, but has not yet been directly observed experimentally. He we model its formation via Three-Body Recombination of cold and trapped H− ions colliding with H2 molecules in the presence of a buffer gas of He atoms.
Molecular Auger Interferometry
Authors: Khokhlova M , Cooper B , Ueda K , Prince K C , Kolorenč P , Ivanov M , Averbukh V
Published: June 2020

Synopsis

We propose a theory of interferometric measurement of a normal Auger decay width in molecules. Molecular Auger interferometry is based on the coherent phase control of Auger dynamics in a two-colour (ω/2ω) laser field. We show that, in contrast to atoms, in oriented molecules of certain point groups (e.g. CH3F) the relative ω/2ω phase modulates the total ionisation yield. A simple analytical formula is derived for the extraction of the widths of Auger-active states from a molecular Auger interferogram, avoiding the need of either attosecond or high-resolution spectroscopy.
Near-saddle-point-energy single- and two-photon Stark spectra of Sr
Authors: Spasopoulos D , Kalaitzis P , Cohen S
Published: June 2020

Synopsis

We present single-photon ionization Stark spectra of Sr as a function of static electric field strength and just above the saddle-point-energy. The spectra exhibit a significant number of avoided crossings between Stark resonances, superimposed on an ionization background due to the continuum excitation. The latter may be avoided by employing single- and two-photon ionization in conjunction with phase sensitive coherent control techniques. This scheme will lead to the isolation of the resonances in differential ionization cross section measurements.
Combined MCDHF-CI and MBPT calculations for n=4 to n=3 x-ray transitions in Ni-like tungsten
Authors: Kozioł K , Rzadkiewicz J
Published: June 2020

Synopsis

The 4d → 3p, 4p → 3s, and 4f → 3p x-ray transitions in Ni-like tungsten ions have been studied theoretically. The Multiconfiguration Dirac–Hartree–Fock method and the large-scale relativistic Configuration Interaction and Many Body Perturbation Theory methods have been employed in order to take into account electron correlation effects on the lines wavelengths.
Photodetachment Studies of Ir− Ions at DESIREE
Authors: Kristiansson M K , Sundberg J , Hanstorp D , Eklund G , Cederquist H , Zettergren H , Schmidt H T
Published: June 2020

Synopsis

Anions of iridium were stored in the cryogenic storage ring, DESIREE [1, 2, 3] and investigated using laser photodetachment. The ions were stored for up to 2000 seconds and the relaxation of several metastable states were studied by selecting different photon energies. The threshold of the previously not observed 3P2 level is located and the lifetime of this sate is found to be longer than the storage time of the ion beam. We also find that a state exists higher in energy than the previously known level with a lifetime in the range of hundreds of milliseconds.
Determination of the electron affinity of astatine
Authors: Leimbach D , Rothe S , Sundberg J , Hanstorp D
Published: June 2020

Synopsis

Astatine is a promising candidate for targeted alpha therapy in nuclear medicine. However, due to its scarce nature, some of its fundamental properties that determine its chemical characteristics such as the electron affinity, the binding erergy of the additional electron in a negative ion, are still unknown. Here we present the method and results of the first measurement of the electron affinity of astatine, performed with the Gothenburg ANion Detector for Affinity measurements by Laser PHotodetachment (GANDALPH) at CERN-ISOLDE.
Photodissociation processes of O2
+(H2O) studied by ion imaging experiments
Authors: Nakashima Y , Nakano M , Okutsu K , Ito Y , Misaizu F
Published: June 2020

Synopsis

Photodissociation processes in the visible and ultraviolet region of water-oxygen molecular complex ion, O2
+(H2O), were studied by ion imaging experiments and theoretical calculations. Two fragment ions, H2O+ and O2
+, were observed in the experiment; the former fragment ion was produced by direct dissociation after excitation, whereas the latter was generated by nonadiabatic transitions from the initially excited states to the lower electronic states.
Investigating the CO trimer geometry using Coulomb imaging technique
Authors: Fléchard X , Méry A , Gervais B , Guillous S , Kumar V , Matsumoto J , Rangamma J , Ropars F , Shiromaru H , Cassimi A
Published: June 2020

Synopsis

The Coulombic explosion of multi-charged (CO)3q+ molecular ions produced in low energy collisions with Ar9+ projectiles was investigated using recoil ion momentum spectrometry (RIMS). A preliminary analysis of the data clearly shows a dominant triangular cyclic structure. Events that may correspond to a linear chain are also observed, but the latter could as well originate from false coincidences, associated to the fragmentation of dimers. A careful analysis of this source of background is proposed to disentangle trimer fragmentation events from false coincidences.
Formation of positive and negative ions in the gas phase of D-ribose by low-energy electrons
Authors: Chernyshova I , Kontros J , Shpenik O , Demes S
Published: June 2020

Synopsis

Using a hypocycloidal electron spectrometer the total dissociative electron attachment cross section and the ionization cross section for D-ribose molecule were studied in the E<30 eV energy range. A clear structure near zero energy and in the 6.0-9.5 eV range is observed in the dissociative electron attachment cross section. These features appear due to the formation of negative ion fragments of the molecule. The ionization potential of the D-ribose molecule was determined at 9.74 ± 0.02 eV. In the total ionization cross section weak features are observed, which most likely due to the formation of positive ion fragments of the initial molecule.
K α1,2α3
and K
hα1,2 satellite transition energies and rates for Ar and Ca
Authors: Kozioł K , Rzadkiewicz J
Published: June 2020

Synopsis

The calculations of radiative energies and transition rates for Kα 1,2α3
and Khα1,2
satellite (Mi, M2,3, and N1
spectator holes) lines for Ar and Ca have been carried out by using the GRASP2K and AMBIT codes. The influence of electron correlation on transition rates has been studied.
The generalized two-photon excitation cross-section of Xe revisited
Authors: Blondel C , Alkhoury J , Jannaud T , Drag C
Published: June 2020

Synopsis

Two-photon absorption laser-induced fluorescence (TALIF) is a technique commonly used for density and/or temperature diagnostics, mainly of oxygen atoms, in flames and plasmas. Usually, density measure-ments are based on the comparison with the signal obtained, at a similar wavelength, in pure xenon. The cross-section of xenon thus appears a key parameter, the measure of which has not been consolidated by independent measurements. The present experiment is a direct measurement of this two-photon cross-section.
Relation between the spatial shape of excited molecular orbital and molecular-frame electron scattering cross section
Authors: Watanabe N , Yamada S , Takahashi M
Published: June 2020

Synopsis

We report the molecular-frame electron scattering cross sections of the 2σg→1πg excitation in O2 and N2, obtained using an electron-ion coincidence technique. The vector correlation between the scattered electron and the fragment ion has been measured at incident electron energy of 1.4 keV. The results exhibit clear molecular-orientation dependence reflecting the nodal structure of the 1πg orbital. It strongly suggests that the electron-ion coincidence technique can provide a powerful tool to investigate spatial shapes of unoccupied molecular orbitals.
Complex scaling in relativistic calculations of cross sections for electron-ion recombination processes
Authors: Bondarev A I , Zaytsev V A , Shabaev V M , Ma X
Published: June 2020

Synopsis

We present an approach to calculate cross sections for electron-ion recombination processes. It is based on the combination of relativistic many-body perturbation theory and complex scaling method. A preliminary comparison between measured and calculated spectra for the electron-ion recombination rate coefficients for Be-like Ca will be given.
Electron induced excitation of Furfural (C5H4O
2)
Authors: Modak P , Singh A , Antony B
Published: June 2020

Synopsis

The present study reports excitation cross section for three low-lying excited states of furfural (C5
H4
O2). These states have a significant contribution to the elastic channel as well as dissociation processes. R-matrix method is used to study the e-C5H4O2 problem under configuration interaction (CI) approximation. The ground state geometry is considered for the construction of Hamiltonian of the problem. Results show resonances for these sates.
Photoionization of Ti3+: β parameter and Momentum Transfer
Authors: Eissner W , Vo Ky L
Published: June 2020

Synopsis

Key issue is the presentation of the unpublished 4 angular factors arising from the 4 paths when momentum transfer induces asymmetry β in photoionization calculations. They require functional expansions such as the frozen cores approach which are not bedevilled by the prior-post dilemma. It is essential to consider all magnetic 2-body terms in the Breit-Pauli hamiltonian that contribute to finestructure.